Rotary-drum-filtering apparatus



y l' l ,536,739 my 269 3927 L, HERTENBEIN ROTARY DRUM FILTERING APPARATUS .Filed June 29. 1925 2 Sheets-Sheet 1 n [i s n l. glsg July im wzl L. HERTENBEIN ROTARY DRUM FILTERING APPARATUS Filed June 29, 1925 2 Sheets-Sheet 2 Figa.

'Pastas .my 2s, 1927. 7 y r UNITED [STATI-:sV

PATENT *oFl-lcE.

' 'LEON Hammam, or LavALLoIsLrnmr, ramon.

Application lecl J'une 29, 1925, Serial No. 40,48%,fand in France my 8,' 19M.

y. The present invention relates to apparatus l for the extraction in tlie form of sludge of solid substances suspended in liquids, -of

` the type .comprising a horizontaldrumwith filtering sui-face, revolving'in a vat cont-ain ing liouid charged with solid substances in suspension, the drum being subgected to suction for causing a layer of material in the form of sludge to adhere to the filtering surface, and the suction being followed by a period of blowing or pressure. for detaching from the filtering surface the sludge material removed by means of a. roller revolving in contact with this surface.

v The inventionrelates more particularly to a means for removing the sludge from the i filtering drum in the casewhere the Adrum consists of a cylinder having an annular.

transverse section includingr a filterin" surface on both its interior and exterior face.

In devices `of this character up to the present, in order to remove the solid material adhering to the interior filtering surface of the drum, such material has been submitted solelv to the action of air forced between the two filtering surfaces in order to remove this matter.

In this manner, however, there has been obtained only an incomplete removal of the material since in drying on the filteringsurface, as soon as such surface leaves the liquid being treated, the sludge cracks, and the compressed air-escapes through these cracks without properly 'removing the material.

It has also been proposed to submit the material adhering to the interior filtering `surface to the action of a washing liquid in such a manner as to complete the action caused by the compressed air on the material, in order to detach thesludge from the filtering surface. However, in this case the material collected by filtration is obtained only in a condition of dilution by the washing liquid. This arrangement may be useful in the case where it is desired only to recover the liquid treated ,in the filtering apparatus. However, it does not permit directly obtaining the material adhering to the interior filtering surface of the drum, iii a more or less solid state.

According to this invention the means for removing the sludge on .the two filtering surfaces of the drum comprise two rollers dis vfrom cracking or checking.

functioning lfor'reinoving the solid matteri from the two filtering surfaces.

In this manner it is poible to directl collect the material adhering to the two .0

tering surfaces off the drum. The air forced 'into theilrum between the two filtering surfaces, in the region where it is desired to produce removal of the solid materials,

causes such materials to adhere to the rollers, 5

which'l rollers by bearing against the ltering surfaces, prevent -the lager of 'sludge s a result the solid material is directly recovered in a 4concentrated state, free from excess water,

and in a complete manner.

The annexed drawin represents merely by wa of example one orm of construction accor ing to the invention.

/' Figure l is a view in'transverse section u of tle apparatus along the line 1,-1 of Figure Figure 2 isa view thereof in longitudinal section along the line 2-2 of Figure 1 parts .o

,ment of rotation at a suitable speed around a horizontal a xis :1iin the interiorof a vat b containing the liquid charged with solid substances in suspension; this vat b supports a stationary horizontal shaft c upon 9 which is mounted rotatably a hub d integral with arms d1 which support the filtering drum A. i i e The latter is constituted by a'cylinder of annular transverse section, formed b a series of boxes a juxtaposed at the periphery of the drum; these boxes are fitted for the whole o f their lengthrinto I-'section bars al2 fixed at the extremities of the arms d1 of the hub d, the bars being arranged between the boxes a and parallel to the longitudinal axis of the drum for the whole of the length of the boxes.

The exterior and interior longitudinal walls a1 and az'respectively of each box are 105 constituted for example by perforated sheet metal cover with a filtering fabric; they mav likewise be made of any suitable filtering material.

The filtering drum A thus supported at one end by the arms all is supported at its other end by a circulartrack e formed by a U-section member lixedupon the inner flanges of the I-members d2 supporting tne drum boxes; this track epasses over rollers e1 arranged internally 1n relation to the drum. Y

Instead of being thus suspended at 1 ts upper part, the drum A might likewise be 'supported at i lower part y rollers upon which there -would rest a track secured externally of the drum upon the I-bars d2.

This arrangement allows easy and rapld assembly and demounting of the iltermg boxes a which can be introduced endwise (from the right in Figure 1 between the I-bars dz, between which they are located, or withdrawn by an opposite movement for cleaning or replacement in case of necesslty.

To the end of each box a there are connected three pipes one f1 at thecentre and two others f2 near the ends. All the plpes f1, corre 'onding to the dilerent boxes, are connecte to a sleeve g mounted so as to rotate with the drum A upon. the iixed horizontal shaft o; in the` thickness of this sleeve g, which continues through a rbearing b1 fixed to the vat b, there are formed, inthe different radial planes of the pipes f1, passages g1 connected to these pipes f1 and extending to register in turn with a d1stribution port h1 of a given angular extent in the interior of a stationary sleeve la. and connected tol a pressure or blowing apparatus (not represented). Similarly all the pipes f `of the ltering boxes connect with corresponding passages g2 formed 1n the thickness of the sleeve g and extending to register in turn with a distribution port i1 of suitable` angular dimensions in the interior of' a stationary sleeve connected to a suction device (not represented).

During the rotation 4of the drum, the boxes a are placed in communication at the desired moments with the suction and pressure apparatus respectively throu h the pipes f2, the passages g2 and -the dlstribution port i1, and by the pipes f1, the Passages g1 and the distribution port h1. Thev sludge which under the action of the suction has adhered to the filtering surface of the boxes a during their period of immersion in the liquid, tends to become detached therefrom under the effect of the pressure produced in these boxes after they have left `the liquid; this` sludge is removed from the filtering surface of the drum by two rollers k and Z arranged parallel to and facing one another, the one 7cexternally of the drum and the other Z internallyof the latter. The first rollerv removes the layer of sludge from the outer face a1 and the other from the inner faceaz of the drum filtering boxes; these two rollers c Z revolve at the' same peripheral speed as the drum, being maintained in contact with the corresponding faces ofthe drum, the first' c by its own weight and the other Z due tothe fact that its spindle'l1 is mounted by means of suitable spring-pressed bearings l upon the arms Z..carried by the stationar shaft c. The tworollers c and Z are 'pre erably located as shown tolone side of the axial vertical plane y-z/v of the drum and behind this plane in relation to the direction of rotation of the drum (Figure 1) as has been described in the specification of the French Patent 574,67 8 filed in the above namev on the 12th March 1923 (British PatentNo. 212,907)4 for the single removal roller emplo ed in that case.

'lille caked sludge removed by the roller la is detached from the latter by a scraper k1l which causes it to fall upon an inclined plate a2. The sludge removed by the roller Z falls intoa gutter or channel m arranged horizbntally below the'roller and comprising at its bottom part an Archimedean screw conveyor m1 which effects the removal of the sludge. This gutter m is extended laterally (Figure l) at m2 on the side situated in advance of the roller Z in relation to-the direction of rotation of the drum,`in such a way that the gutter receives any sludge which might by itself at the moment of the application of pressure become detached( from the inner face of the drum, before bein removed from the latterby the roller Z.

gs can readily be understood, this drum with external and internal filtering surfaces, has an output almost double that of the rotary lters in which only the outside surface of the drum is utilized for the filtration.

It is to be understood that without departing from the principle of the invention there may be applied thereto a large number of modifications of detail in theconstruction described and illustrated, for example as regards the construction and `method of mounting the filtering boxes, the method of supporting the drum, the arrangement utilized for producing the suction and the pressure in the interior .of these boxes and so on. A

What I claim is:

1. In a rotary drum filtering apparatus for the extraction, in the form of sludge, of solid substances suspended in liquids, the

combination of a drum having a cylinder of annular cross section provided with a filtering' surface upon its external and internal faces, suction means to cause the solid matter suspended in the li uid to adhere in the form of sludge to both tering surfaces over the major part ofthe-circumference of the drum, ressure means, acting on the emerged area o the drum upon'the solid matter adhering to the filtering surfaces and arran ed to detach such matter therefrom, two ro ers arranged parallel to and facin one another, one on the exterior and the o er in the interior of the drum, in contact with the ex? a fixed shaft carrying the drum, a hub rotatably mounted at one end of the shaft, radial arms secured to the hub, spaced members arranged alon Y the generatrices of the drum and carried y the radial arms, and boxes fitted between the spaced members at the periphery of the drum and provided with outer and inner walls having filtering surfaces.

3. In'a rotary drum filtering apparatus for the extraction, in the form of sludge, of solid substances suspended in liquids, a drum having a cylinder of vannular cross section, a fixed shaft carrying the'drum, a hub rotatably mounted at one end of the shaft, radial arms secured to the hub, spaced members arranged along the generatrices ot the drum and carried by the radial arms, a circular track fixed to the members at the other end of the drum, rollers supporting the track, and boxes fittedbetween the spaced members at the periphery of the drum and provided with outer and inner walls having filtering surfaces.

4. In a rotary drum filtering apparatus for the extraction. in the form of sludge, of solid substances suspended in liquids, a drum having a cylinder of annular cross section, a fixed shaft carrying the drum, a hub rotatably mounted at one end of the shaft, radial arms secured to the hub, spaced members arranged alon the generatrices of the drum and carried Ivy the radial arms, and boxes fitted between the spaced members at the'- periphery of the drum and provided with outer and inner Walls having filtering surfaces, suction means to cause the solid the form of sludge to both filterin surfaces over the. major part of the circum erence of the drum, pressure means, acting on the emerged area of the drum upon thesolid matter adhering to the filtering surfaces and arranged to detach such matter therefrom, two parallel,l facing rollers at, and in contact with, the exterior and interior filtering surfaces for removing sludge therefrom.

5. In a rotary drum filtering apparatus for the extraction, inthe formof sludge, of

lsolid substances suspended in liquids, a drum having a cylinder of annular cross section, a fixed shaft carrying the drum, a hub rotatably mounted at one end of the shaft, radial arms secured to the hub, spaced members arranged along the generatrices of the drum and carried by the radial arms, a circular track fixed to the members at the other end of the drum, rollers supporting the track, and boxes fitted between the spaced members t the periphery of the drum and provided with outer and inner walls having filtering surfaces, suction means to cause the solid matter suspended in the liquid to adhere in the form of sludge to both filtering surfaces over the major part of the circum ference of the drum, pressure means, acting on the emerged area of the drum upon the solid matter adhering to the filtering surfaces and arranged to detach such matter therefrom, two parallel, facing rollers at, and in contact with, the exterior and interior filtering surfaces for removing sludge therefrom.

In testimony whereof I have signed my name to this specification.

. LEON HERTENBEIN.

` matter suspended in the liquid to adhere in 

